Development of a quality assurance system in radiation oncology: A 12-year experience in a University Hospital.

Purpose: This study aimed to report 12 years of experience in the development of a quality assurance system in radiation oncology in a university hospital.

Material And Methods: We developed the Quality Assurance Program in Radiation Oncology (QUAPRO) in 2008 to detect treatment deviation in the radiotherapy (RT) process with three steps of near-miss detection: simulation and prescription (primary check, PC), treatment planning (secondary check, SC), and treatment delivery process (tertiary check, TC). We transferred our paper-based medical records to electronic-based radiotherapy information systems (RTISs) in 2013.

Analysis of the planned, delivered dose distributions and quality assurance for helical tomotherapy and volumetric modulated arc therapy in locally advanced non-small cell lung cancer.

Background: With full access to both helical tomotherapy (HT) and volumetric modulated arc therapy (VMAT), we compared locally advanced non-small cell lung cancer (LA-NSCLC) treatment plans and verified the plans using patient-specific pretreatment quality assurance (PSQA).

Materials And Methods: For each of the seventeen patients included in the study, two treatment plans (i.e.

The advantages of abdominal compression with shallow breathing during left-sided postmastectomy radiotherapy by Helical TomoTherapy.

Background: Left-sided post-mastectomy radiotherapy (PMRT) certainly precedes some radiation dose to the cardiopulmonary organs causing many side effects. To reduce the cardiopulmonary dose, we created a new option of the breathing adapted technique by using abdominal compression applied with a patient in deep inspiration phase utilizing shallow breathing. This study aimed to compare the use of abdominal compression with shallow breathing (ACSB) with the free breathing (FB) technique in the left-sided PMRT.

Effect of Deformation Methods on the Accuracy of Deformable Image Registration From Kilovoltage CT to Tomotherapy Megavoltage CT.

Introduction: The registration accuracy of megavoltage computed tomography images is limited by low image contrast when compared to that of kilovoltage computed tomography images. Such issues may degrade the deformable image registration accuracy. This study evaluates the deformable image registration from kilovoltage to megavoltage images when using different deformation methods and assessing nasopharyngeal carcinoma patient images.

Intermediate-term results of trans-abdominal ultrasound (TAUS)-guided brachytherapy in cervical cancer.

Objectives: To report the intermediate-term results of trans-abdominal ultrasound (TAUS)-guided brachytherapy in cervical cancer.

Materials And Methods: Ninety-two patients with cervical cancer (stage IB-IVA, according to FIGO staging), were treated by curative radiotherapy from February 2012 to June 2015. All patients were treated with whole pelvic radiotherapy to 50 Gy in 25 fractions and central shielding after 44 Gy, in combination with TAUS-guided brachytherapy, in order to escalate the total dose (EQD2) to the minimal dose at cervical points (in EQD2 concepts) defined by TAUS, while maintaining low doses to ICRU bladder and rectal points.

Evaluation of Deformable Image Registration (DIR) Methods for Dose Accumulation in Nasopharyngeal Cancer Patients during Radiotherapy.

Introduction: Deformable image registration (DIR) is used to modify structures according to anatomical changes for observing the dosimetric effect. In this study, megavoltage computed tomography (MVCT) images were used to generate cumulative doses for nasopharyngeal cancer (NPC) patients by various DIR methods. The performance of the multiple DIR methods was analysed, and the impact of dose accumulation was assessed.

Accuracy of eight deformable image registration (DIR) methods for tomotherapy megavoltage computed tomography (MVCT) images.

Introduction: The application of deformable image registration (DIR) to megavoltage computed tomography (MVCT) images benefits adaptive radiotherapy. This study aims to quantify the accuracy of DIR for MVCT images when using different deformation methods assessed in a cubic phantom and nasopharyngeal carcinoma (NPC) patients.

Methods: In the control studies, the DIR accuracy in air-tissue and tissue-tissue interface areas was observed using twelve shapes of acrylic and tissue-equivalent material inserted in the phantom.

The using of megavoltage computed tomography in image-guided brachytherapy for cervical cancer: a case report.

We present a case of cervical cancer treated by concurrent chemoradiation. In radiation therapy part, the combination of the whole pelvic helical tomotherapy plus image-guided brachytherapy with megavoltage computed tomography of helical tomotherapy was performed. We propose this therapeutic approach could be considered in a curative setting in some problematic situation as our institution.

University Cooperation Platform (UCP) between Christian-Albrechts-University Kiel (Germany) and Chiang Mai University (Thailand): implementation of image-guided gynecological brachytherapy.

Starting in 1999, the University Cooperation Platform (UCP) implemented an exchange program of researchers and clinicians/physicists between the Christian-Albrechts-University Kiel in Germany and Chiang Mai University in Thailand, to initiate a sustainable base for long-term development of image-guided brachytherapy and in general for high-technology radiotherapy in Chiang Mai. A series of UCP protocols, based constructively on each other, were performed and evaluated at intermediate term follow-up. The first protocol, addressing computed tomography (CT)-optimized brachytherapy for advanced cervical cancer (n = 17), showed a significant reduction of D2cc for the bladder and sigmoid (p < 0.

A comparative planning study of step-and-shoot IMRT versus helical tomotherapy for whole-pelvis irradiation in cervical cancer.

The aim of this study was to compare the dosimetric parameters of whole-pelvis radiotherapy (WPRT) for cervical cancer between step-and-shoot IMRT (SaS-IMRT) and Helical Tomotherapy™ (HT). Retrospective analysis was performed on 20 cervical cancer patients who received WPRT in our center between January 2011 and January 2014. SaS-IMRT and HT treatment plans were generated for each patient.

A dosimetric comparison of two-phase adaptive intensity-modulated radiotherapy for locally advanced nasopharyngeal cancer.

The purpose of this investigation was to evaluate the potential dosimetric benefits of a two-phase adaptive intensity-modulated radiotherapy (IMRT) protocol for patients with locally advanced nasopharyngeal cancer (NPC). A total of 17 patients with locally advanced NPC treated with IMRT had a second computed tomography (CT) scan after 17 fractions in order to apply and continue the treatment with an adapted plan after 20 fractions. To simulate the situation without adaptation, a hybrid plan was generated by applying the optimization parameters of the original treatment plan to the anatomy of the second CT scan.

Two-year results of transabdominal ultrasound-guided brachytherapy for cervical cancer.

Purpose: To report the preliminary results of transabdominal ultrasound (TAUS)-guided brachytherapy (BT) in cervical cancer.

Methods And Materials: Twenty-nine patients with cervical cancer Stage IB-IVA according to The International Federation of Gynecology and Obstetrics staging were treated by radical radiotherapy from February 2012 to December 2012. Treatment was composed of WPRT to 50 Gy in 25 fractions and central shielding after 44 Gy in combination with TAUS-guided BT to optimize the total dose (equivalent dose of 2 Gy [EQD2]) to the minimal dose at cervical points (in EQD2 concepts) defined by TAUS ≥80 Gy while maintaining low doses to the ICRU report no.

The association of rectal equivalent dose in 2 Gy fractions (EQD2) to late rectal toxicity in locally advanced cervical cancer patients who were evaluated by rectosigmoidoscopy in Faculty of Medicine, Chiang Mai University.

Purpose: To evaluate association between equivalent dose in 2 Gy (EQD2) to rectal point dose and gastrointestinal toxicity from whole pelvic radiotherapy (WPRT) and intracavitary brachytherapy (ICBT) in cervical cancer patients who were evaluated by rectosigmoidoscopy in Faculty of Medicine, Chiang Mai University.

Materials And Methods: Retrospective study was designed for the patients with locally advanced cervical cancer, treated by radical radiotherapy from 2004 to 2009 and were evaluated by rectosigmoidoscopy. The cumulative doses of WPRT and ICBT to the maximally rectal point were calculated to the EQD2 and evaluated the association of toxicities.

The effect of central shielding in the dose reporting for cervical cancer in EQD2 era.

Purpose: To evaluate the cumulative dose at point A for three and four centimeters central shielding.

Material And Methods: The plans of external beam radiotherapy plus conventional intracavitary brachytherapy were performed. Three or four centimeters central shieldings (after 44 Gy) were applied to the standard whole pelvis irradiation.

Image-guided brachytherapy (IGBT) combined with whole pelvic intensity-modulated radiotherapy (WP-IMRT) for locally advanced cervical cancer: a prospective study from Chiang Mai University Hospital, Thailand.

Purpose: A report of preliminary results and toxicity profiles using image-guided brachytherapy (IGBT) combined with whole pelvic intensity-modulated radiation therapy (WP-IMRT) for locally advanced cervical cancer.

Material And Methods: Fifteen patients with locally advanced cervical cancer were enrolled into the study. WP-IMRT was used to treat the Clinical Target Volume (CTV) with a dose of 45 Gy in 25 fractions.

Intermediate-term results of image-guided brachytherapy and high-technology external beam radiotherapy in cervical cancer: Chiang Mai University experience.

Objective: To evaluate the outcomes of image-guided brachytherapy combined with 3D conformal or intensity modulated external beam radiotherapy (3D CRT/IMRT) in cervical cancer at Chiang Mai University.

Methods: From 2008 to 2011, forty-seven patients with locally advanced cervical cancer were enrolled in this study. All patients received high-technology (3D CRT/IMRT) whole pelvic radiotherapy with a total dose of 45-46 Gy plus image-guided High-Dose-Rate intracavitary brachytherapy 6.

Preliminary results of MRI-guided brachytherapy in cervical carcinoma: the Chiangmai University experience.

This study was performed to evaluate the feasibility of magnetic resonance imaging (MRI) in the treatment planning of image-guided brachytherapy for cervical carcinoma. Seventeen consecutive patients with locally advanced cervical cancer were enrolled in the study. Fifteen patients could be evaluated.

Preliminary results of conformal computed tomography (CT)-based intracavitary brachytherapy (ICBT) for locally advanced cervical cancer: a single institution's experience.

Intracavitary brachytherapy using tandem and ovoids is an important component of definitive treatment for cervical cancer. In the present study, we analyzed the dose-volume histograms (DVHs) of the tumor volume and organs at risk including the sigmoid colon by CT-based treatment planning for high dose rate (HDR) intracavitary brachytherapy (ICBT) in cervical cancer. Seventeen patients with carcinoma of the cervix uteri were treated with external beam radiotherapy plus concurrent chemotherapy.

Dosimetric verification of radiotherapy treatment planning systems: results of IAEA pilot study.

Background And Purpose: The methodology developed by IAEA for dosimetric quality control of treatment planning systems has been tested in different hospitals through a pilot study. The aim was to verify the methodology and observe the range of deviations between planned and delivered doses in 3D conformal radiotherapy in situations close to a clinical setting.

Material And Methods: The methodology was based on an anthropomorphic phantom representing the human thorax, and simulates the whole chain of external beam radiotherapy treatment planning activities.